Core forming mechanism



R. N. BROWN June 2, 1931.

CORE FORMING MECHANISM Filed Feb. 2'7, 1930 2 Sheets-Sheet @QQQQ June1931. R. N. BROWN CORE FORMING MECHANISM Filed Feb. 27. 1930 2Sheets-Sheet 2 amnioc- Patented June 2, 1931 UNITED STATES PATENT OFFICEROBERT N. BROWN, OF DETROIT, MICHIGAN, ASSIGNOR TO PACKARD MOTOR! CARCOMPANY, OF DETROIT, MICHIGAN, A. CORPORATION 01 MICHIGAN CORE FORMINGMECHANISM application filed February 27, 1930. Serial No. 431,935.

This invention relates to sand core forming means and more particularlyto means for holding and clamping the parts of a collapsible core formor box during the operation of blowing sand therein.

It is a general object of the present invention to provide a novel andimproved core forming mechanism,

One of the important features of the invention comprises the use of ayoke to receive and enga e the parts of a collapsible core box toget erwith means on a sand transfer member for cooperating with both the yokeand the core box to tightly clamp the parts thereof to ether.

Another feature 0 the invention comprises the arrangement of a yoke withupwardly extending arms, mounted on a movable platform and adapted toreceive the bottomand sides of a collapsible core form, together with amovable sand conveyor which can be positioned above the core box andwhich is provided with a cover for the same and means to pass betweenthe core box and at least one of the arms of the yoke to wedge the corebox parts tightly together.

Other and further features and objectsof the invention will become moreapparent to those skilled in the art upon a consideration of theaccompanying drawings and following specification, wherein is shown asingle exemplary embodiment of the invention, with the understanding,however, that such changes may be made therein as fall within the scopeof the appended claims without departing from the spirit of theinvention.

In said drawings:

Figure 1 is a perspective view of a core blowing machine showing thepresent invention incorporated therein; and

Figure 2 is a fore and aft vertical section 2 through the machine.

Referring to the drawings it will be seen that the machine comprises abase 10 supporting a pairvof spaced vertical columns 11. Attached to thebase and the forward edge of the vertical columns is a pneumaticcylinder 12 and operatin therein is a piston 13 having a top or ta 1e 14carrying the yoke 15 secured thereto. The upper ends of the columns areinclined forwardly and merge into the hollow. blowing head 16 which isdirectly positioned above the center of the table 14.

A sand hopper 17 is mounted on the columns to the rear of the blowinghead and has its 0 en mouth at the same level as the mouth 18 o theblowing head which is open. This hopper isada ted to contain a suitablecore sand, preferably a natural bond sand and may be provided with anyconvenient form of rapper to insure a steady flow of sand from thehopper when desired.

A sand conveyor or transfer member 20, in the form of a hollowelliptical cylinder is movable from a position beneath the hopper monthto a position beneath the blowing head and for th1s purpose the transfermem ber 20 is supported from a frame 21 provided with rollers 22 looselyrunning in ways 23 in the guides 24 supported between the columns. Asuitable pneumatic cylinder 25 is provided with a piston attached to theconveyor by means of the piston rod 26. The cylinder is convenientlysupplied with compressed air by means of a selective valve to either endthereof to move the conveyor from one position to the other. The back ofthe frame 21 is extended as at 28 to form a closure slide for the mouthof the hopper when the conve or is moved away.

In its orward position the sand transfer 1 veniently fit together withthe ends between the sides and held by dowel pins or merely haveengaging tongues and grooves so that they can be quickly assembled andthen disassembled after the core is formed so that it can be removedintact.

With the core box parts in position on the yoke, with the piston 13lowered and the sand a perforated the piston 13 is lifted and togetherwith it.

the yoke and core box. This causes the upper edges of the core box sidesand ends to engage with the plate 40 which is secured to the peripheralflange 41 on the bottom of the sand transfer member. This late 40 hasone'or more small openings 42 t erein through which the sand is blown into.the core box, but these openings are of such size that the normalconsistency of the sand prevents it from falling through, particularlysince the plate 40 may rest on the spacing web 43, between the columns11, when the sand conveyor is being filled. V 7

When the piston 13 is raised to engage the core box with the plate 40,the whole sand transfer member is slightly elevated due to the loosenessof the rollers 22 in their ways so that the upper end ofthe sandtransfer member, which already registers withfthe opening in the blowinghead, is caused to tightly engage it and form anair-tight joint with theassistance of a gasket 45 if desired.

The blowin head is provided with'a' suitable bathe 46 .and an air inletconduit 47 so that air can be blown at great pressure and properlydistributed over the surface of the sand in the transfer member to blowit into the core box which is perforated in a numberof places, notshown, to permit of theescape of the air, as the sand is deposited toform the core. Under the high pressure of the air the sand is driventhrough the openings 42 in the plate 40 and delivered into a the corebox.

It is highly desirable, in order to facilitate operations, that the corebox be arranged to be clamped together without any separate means beingapplied thereto for the purpose. It must be held quite securely togetherduring the blowing operation, owing to the high pressure of air neededto properly deposit the natural bond sand, andfor this purpose it I isconvenient to have one arm of the yoke,

preferably 31 with a face 51 of such shape as to enga e over a largearea of the side plate 36 o the core box form and to have thecorresponding face 48 on the opposite arm of the yoke inclined as shownopposite to the inclination of theouter face 49 of the side member 35 ofthe core box. A wedgef50 is then provided of the proper inclination-tofit between the surfaces 48 and 49 so that when the wedge is tightlypressed in place the core box is securely clamped between it and theopposite arm of the yoke.

The wedge 48 has mounted thereon a pair extensions of the flange 41 onthe bottom of the sand transfer member. The rods may be convenientlyprovided on their upper ends with stop nuts 54 to engage with the uppersurface of the flange as the yoke is lowered to assist in withdrawingthe wedge. Mounted on the rods between the undersurface'of the flange 41and the upper face of the wedge 50 are the strong coil springs 55 whichare instrumental in forcing the wedge into position as the yoke iselevated to bring the upper edges of the core box in engagement with theclosure plate 40 therefor on the sand transfer member.

It will beunderstood that suitable valves and controls are provided toadmit air to the respective ends .of the cylinder 25 and to the maincylinder 12 which lifts the yoke and the corezbox. The vertical movementof the 1yoke and the core box may also provide for owering the core boxto such a position that it can be conveniently slid off onto conveyorssuch as the conventional roller conveyors which thus eliminates handlingof the heavy parts any more than necessary and permits the core in itsbox to be rolled away for further treatment and use. .It willbe'understood that it is also necessary to lower the yoke inorder thatthe sand transfer member willbe free to move back to the hopper foradditional sand so that the core box will not interfere with the wedgecarried. on the a sand transfer member laterally movable over thecorebox when the support is lowered,

and a wedge device on said member to pass between the core box and oneof the yoke arms, to clamp the core box parts together when the supportis elevated to bring the core box I in engagement with the transfermember.

2. A. core forming machine, including, in combination, a base, a tablevertically movable-in respect to said base, a yoke secured to said tableand having spaced arms to receive a collapsible core box,=a blowing headrigidly supported from said base above the said yoke, a sand transfermember laterally movable to a position beneath said head and'over saidyoke, means on said transfer member to close the top of said core boxwhen the table is elevated to engage the core box with the transfermemberand press the transfer member into engagement with said head, andmeans on said transfer member to cooperate with'the yoke and core box toclamp the parts of the core box together as the table is elevated.

3. A core forming machine including, in combination, a verticallymovable yoke having spaced arms to receive a collapsible core box, ablowing head rigidly supported above said yoke, a sand transfer membermovable to a position between said head and core box, means on'saidtransfer member to close the top of the core box, means on the transfermember to cooperate with the core box parts and the yoke to clamp thecore box together, and means to elevate the yoke when the transfermember is above it to force the core box,

transfer member, and head into cooperating engagement.

4. A core forming machine including, in combination, a verticallymovable member adapted to receive a collapsible core box, a blowing headaligned with the movable member, a movable sand receptacle adapted toregister with the blowing head and the core box, and means on saidreceptacle to cooperate with the movable member and the core box toclamp the core box together when the movable member is raised to engagethe core box and receptacle.

5. A core forming machine including, in combination, a verticallymovable member adapted to receive a collapsible core box, a blowing headaligned with the movable member, a movable sand receptacle adapted toregister with the blowing head and the core box, and resiliently mountedmeans on said receptacle to cooperate with the movable member and thecore box to clamp the core box together when the movable member israised to engage the core box and receptacle.

6. A core forming machine including, in combination, a verticallymovable member adapted to receive a collapsible core box, a blowing headaligned with the movable member, a movable sand receptacle adapted toregister with the blowing head and the core box, and a wedge on saidreceptacle to force the core box into lateral engagement wi'lh themovable member when the movable member is elevated to press the core boxagainst the receptacle and the receptacle against the blowing head.

7. A core forming machine comprising a vertically movable member adaptedto receive a core form, a blowing head, a sand receptacle adapted toperiodically register with the form on the movable member and theblowing head, wedge means on said receptacle to clamp the parts of theform as the member'is elevated, and means to elevate the movable member.

8. A core forming machine comprising a vertically movable piston, a yokeon the top of said piston to loosely receive the parts of a. core form,a head above said yoke, a sand receptacle movable to a position betweensaid head and yoke when the yoke is lowered, means to move the pistonand yoke upwardly form with one arm of the to engage the form with thereceptacle, and means associated with said receptacle to engage the yokeand form to press them into.

tight engagement laterally when the yoke is elevated.

9. A core forming machine comprising a vertically movable yoke toloosely receive the parts of a core form, a sand receptacle movablelaterally from and to a position over said yoke when the yoke islowered, means on said receptacle to close the top of said form, meansassociated with said receptacle to engage the yoke and form to press theform parts tightly together when the yoke is elevated, and means toraise and lower the yoke.

10. A core forming machine comprising a pneumatically operated pistonadapted to move vertically, a yoke on the top of said piston, acollapsible core form adapted to rest in said yoke between the armsthereof, a sand receptacle movable laterally from and to a positionabove said form and yoke, means on said receptacle to form a closure forthe top of said form, and means carried by said receptacle to causetight engagement of the yoke when the yoke and form are elevated.

11. A core forming machine comprising a pneumatically operated pistonadapted to move vertically, a yoke on the top of said piston, acollapsible core form adapted to rest in said yoke between the armsthereof, a sand receptacle movable laterally from and to a positionabove said form and yoke, means on said receptacle to form a closure forthe top of said form, and a wedge device mounted on said receptacle topass between one arm of the yoke and the form to clamp the form togetherwhen the yoke and form are elevated. a

12. A core forming machine comprising a pneumatically operated pistonadapted to move vertically, a yoke on the top of said piston, acollapsible core form adapted to rest in said yoke between the armsthereof, a sand receptacle movable laterally from and to a positionabove said form and yoke, means on said receptacle to form a closure forthe top of said form, and a spring mounted wedge adapted to pass betweenone arm of the yoke and the form to clamp the form parts together as theyoke is elevated tocause the top of the form to be closed by the meanson the receptacle.

In testimony whereof I hereunto affix my signature.

a ROBERT N. BROWN.

